Next week is London Fashion Week and catwalks again will be full of skinny models. So what does a "size zero" diet do to you? Dawn Porter (right) went on a crash slimming course and found a perverse, and worrying, comfort in her misery.

When I decided to take on the gruesome task of a starvation diet, I was ignorant to believe that hunger would be my only challenge. The hunger actually became a sick comfort to me, a reassurance that I was doing the "right" thing.

But the depression, the loneliness, and the chronic insomnia were the side effects of a dangerously low calorie diet, that made me worry I had flicked a mental switch, that I would never be able to turn back.

Since as long as I can remember I have been a size 12; 5ft 9ins, with really skinny legs, narrow shoulders, reasonably large boobs, a small bum and a sticky out belly, which continued in motion a little longer than I would have liked, after every step that I took.

I am the consummate "apple" shape; a walking, talking Granny Smith, but with enough height to disguise myself as a banana, if I wore a short enough skirt and a clever enough top.

Dawn's diet was the focus of a BBC programme

But where is the line between looking one's best, and taking the whole obsessive body image thing just a touch too far?

The recent "size zero" phenomenon (an American creation which actually translates as a UK size four), gleefully promoted by freakishly large-headed celebs, seems to have spawned a frightening increase in young girls developing eating disorders, as they associate "skinny" with "success".

What happened to making it in life using talent and charm?

How could I show the hordes of young girls what starving themselves actually means; that the short term "gain" of a stick thin frame, had long term detrimental side effects?

I did the unthinkable, and road-tested the size zero lifestyle myself.

Just over eight weeks ago, I introduced a totally new concept of eating into my life, that being - not eating. I decided to go from my usual 1,500 calories a day to an absolute maximum of 500.

By day one I was having headaches, mood swings and demonstrating weird obsessive behaviour... and that was before lunch!

The hunger never goes, but you begin to enjoy it, trust it, and rely on it

Dawn Porter

Everyone knows how they feel when they haven't eaten: moody, groggy, low energy. Well picture that a million times more intense, as it increases with every day that passes.

Life becomes a struggle with temptation, and a battle of self will. An unhealthy obsession with food is the only way to deal with the painstaking monotony of daily life.

The hunger never goes. But you begin to enjoy it, trust it, work with it and rely on it. When your goal is to be thin, the hunger is your best friend.

It's the only thing that assures you that you are working hard enough, because no matter how many ribs you can see in the mirror, it is never enough. There is always further to go.

When I began this journey I was 10st 7lbs, and had a healthy Body Mass Index (BMI) of 22. In just 8 weeks I shot down 17lbs, and reached an unhealthy BMI of 19, which meant that just half a stone more and I would have been so worryingly thin, that some countries would have banned me from the catwalk.

Most alarming was how my confidence got so low. As the project went on, and I apparently got the body I thought I always wanted, I felt more and more self aware and hated the idea of anyone looking at me.

I looked at my body in the mirror and hated it because it was the cause of me feeling so down. I couldn't look at the weight loss as an honourable achievement because I was disgusted in what it took to achieve it.

I think it was then that I truly understood the pressures so many models are under, and how miserable their lives must be as they try to keep up with the super skinny look that their industry demands.

My final weigh-in saw that I had lost 17lbs and 50% of my body fat. Which after everything I had been through strangely, and temporarily, disappointed me. I was nowhere near size zero, and I felt like I had not achieved what I set out to do.

And that's exactly what this is all about: normal women, with normal constitutions set on unachievable goals. And when they don't meet them, they feel like failures.

I could have lost that weight over time, in a healthy, balanced way, and felt wonderful. But being extreme and not giving my body what it needed meant that every effort was futile, and being thin, did not make me happy as you would generally expect.

I was warned to ease myself back into eating slowly, but I can't say I followed that advice. Since ending the diet I have resumed my life as normal. Maybe one day I will try to lose a little more over time. But I never want to go back to how I felt when I was on that diet, and I hope to God, that my experience puts anyone else off trying the same thing. The body needs fuel. Food works, eat it.

Super Slim Me: A Mischief Special is on BBC Three, Wednesday, 7 February at 2100 GMT.

Some of your comments on this story:

Wow, the food diary reads like the diary of an anorexic person. I'm so glad this was an experiment, and not "real life"; and I'm so sorry for all the people who believe that being "size zero" is desirable.Shelley, Preesall, Lancashire

Had I wanted to read about another girl on another unnecessary, unhealthy crash diet, I would have bought one of those "informative" women's magazines instead. A 5' 9" size 12 woman deliberately losing weight? The mixed message in this article makes it nonsensical. How could Dawn Porter have lost that weight "in a healthy way" when it sent her BMI plummeting to 19, and when she refers to it as an unrealistic goal in the first place? Shame on the BBC for this utterly pointless feature.Emma, London

Deep down, if the reason women want to look skinny is cause they think it is attractive, then why doesn't someone carry out a survey of all men in the world. I estimate that over 90% of men would say they prefer a size 10+ over freakish size 6's and 8's. Its women that cause the low self esteem in each otherDom, Basingstoke

Size Zero might suit fashion designers but almost every guy I know doesn't find these skinny girls are attractive. Slim is attractive, yes - but puleeeze! - some feminine curves are essential! But, ironically, breast implants are a big "no thanks" for guys too. So girls, just be yourselves and we'll love you all the more.... Personality counts most of all anyway.Ken, Glasgow

I can quite honestly say I think the whole idea of being a 'size zero' is self-obsessed neurotic! It seems consumer society and the media has taken over the minds of too many people. Those who think that they need to be a size zero, need to have a very good look at their self esteem. You are born the height and size you are, focus on eating healthily and exercise not ridiculous and dangerous trends! It's past stupidity..!Steph, Glasgow

1. 500 k/cal is dangerously low, for any weight loss diet.
2. A BMI of 19 is not unhealthy. It is 'within' the healthy range.Matthew Lake, Cardiff, Wales

Could we all please just try to move away from this national obsession with weight and all the pressure from the media to conform to an unrealistic ideal. That we need dieting and weight loss to give our lives meaning demonstrates just how narcissistic we have all become. The constant promotion of skinny people and the media association of thin-ness with health, success, moral virtue and attractiveness is little more than a daily form of social violence against each and every one of us and it's almost impossible to be accepting of one's appearance when faced with this level of co-ordinated attack on our self-esteem. We live in a massively disordered society where food and body image is concerned - some people are deemed too thin, some too fat, everyone is meant to be trying to change the way they look to appear the same, and I can't think of a single person who is genuinely happy with the status quo - apart from perhaps the shareholders of Weight Watchers and beauty magazines... because as usual it all comes down to money.Rich, Leeds, UK

Eat too much, you get fat. Eat too little, you get thin. Why does the BBC contrive to make a news story out of this every day of the week, every week of the year?Jack, London

There is an easy way to keep off weight and it's the 'healthy' way. Become a vegetarian. I became one over 7 months ago, dropped over 12 pounds in the first two months and haven't gained a pound back. I feel great, finally can wear anything I want, and have the satisfaction of knowing that I no longer consume innocent victims just because we're higher up on the food chain and we can. The greatest thing about becoming a veggie is you can still enjoy delicious foods but you really do become all that much more health conscientious. I think twice about everything I eat now and like work, I eat to live, not the other way around.Tina Ruiz, Annandale, VA USA

If these people don't want to eat their dinners, then I'll gladly have their shares.Chris Boland, Leeds

Silly question - but why actually go on such an extreme diet? The size 0 phenomenon is so dangerous and bizarre, it is beyond parody. Why is air time even given to the idea that women must be on the edge of starvation, to be attractive in clothes? Displaying pictures of super thin model and size 0 celebrities gives weight to the idea that is normal and desirable to be that thin. It is not, it is dangerous and wrong.Emma, Barnsley

The nanny state continues. If someone wants to be a size zero because it makes them happy then let them. I find size 0 women much more attractive personally.Benoit, London

Why the need to slim, when you can exercise and eat healthy! Why do most women feel that they need to persist in dieting, starving themselves to "walking talking sticks" insects. Bring back curvy women and end all this claptrap on size zeros now!!
Women of the UK/world, stop putting yourself under pressure!!
rob, London, England

Why would you want to do such a thing? Size zero, no thanks. Twelve, yes please.Granty, England

Like (I suspect) most men I much prefer the before to the after. I think the real problem is designers who are under the impression that women should look like boys and female editors of the fashion rags who look like bags of bones themselves, so try to convince everybody else they should look like it to. Sorry, I'm feeling very non-PC today!Paul Braham, Southampton

This is the 21st century - use kg not stones and pounds, otherwise we'll never learn!Chris, Bath

What a brilliant article. It's fascinating to read the psychological impact of extreme dieting and the surprisingly underwhelming sense of accomplishment after losing 17lbs in 8 weeks! This should be read by all people desperate to lose weight, to show that losing it fast will not make them happy, it will leave them feeling unconfident, weight-obsessed and incredibly low.Johnny Lyttle, Leeds, UK

Consumerism is all about creating a void and filling it for profit. The body fascism and beauty neurosis industry flogs clothes and makeup to inherently narcissistic and self obsessed young women. The beauty/fashion industry which purports to be emancipating is in fact exploitational. Next time leave that copy of Cosmo/Vogue/Grazia on the shelf and be happier in yourself. Mr Chuffy, London UK

In no way am I condoning the fashion industry's use of unhealthy models, but the fact remains that there are those in the population who are really just that thin, naturally. It is important to make that distinction when looking at thin people--yes, some (especially in the fashion and entertainment industries) will have developed a distorted body image or eating habits, but many every-day women on the street were born genetically to be tall and slim. That explains why Dawn couldn't reach the size zero--her natural body type prevented it from happening.Anonymous, San Francisco, USA

I absolutely agree, but I think we are too one-sided about what weight is unhealthy. Proportionately, there are many more people in the country who put their health at risk by being overweight than underweight. While super-thin is very dangerous, so is putting out the message to teenagers (and grown ups) that it's okay to eat too much and be sedentary. Alison, London

For years I worked for Gap in the UK and they have always stocked a size zero. Always, come the sales, the racks were full of size zero dresses, skirts and trousers and I bet that if were to check the rails today, the same thing would be true.
Jane farthing, Austria

I am a 30year old women who is sick of these super skinny models. I have a naturally thin body, (I have never weighed more than 8 stone in my life, yet I consume over 2000 calories daily). Being thin is not all it is cracked up to be. The constant bitchy remarks from women who think you are starving yourself to be thin. If you go out to eat, people stare to see what you eat, how much you eat and so on. This is before you even get to the issue of buying clothes. Unless you are fairly financially set, clothes shopping is an absolute nightmare. With 3ft of leg and a size 6 waist there is very little choice. Personally I believe that models should look more natural. I understand that some of the models are naturally skinny, but what a difference it would make if we could actually see real women on the catwalk.Samantha , Luton, UK